World powers imposed an arms embargo Tuesday on Yemeni rebels and demanded they relinquish territory seized in a sweeping offensive that forced U.N.-backed President Abedrabbo Mansour Hadi to flee overseas.

The U.N. Security Council vote came soon after Iran, a key ally of the Huthi Shiite rebels, proposed a peace plan for Yemen calling for a ceasefire followed by foreign-mediated talks by all sides.

Fears are growing of a humanitarian disaster in the impoverished state, which sank deeper into violence and chaos after a Saudi-led regional coalition launched an air war on the Huthis and allied rebel troops on March 26.

U.N. rights chief Zeid Ra'ad Al Hussein called Tuesday for investigations into the high level of civilian casualties that account for almost half of the at least 736 deaths recorded in the conflict.

Al-Qaida has sought to exploit the turmoil to expand its foothold in Yemen, a front-line in the U.S. war on the Sunni extremist group.

But in a setback for what Washington considers the deadliest branch of the jihadist network, Yemen-based Al-Qaida in the Arabian Peninsula said its ideological leader Ibrahim al-Rubaish had been killed in a drone strike on Monday.

Russia, which has friendly relations with Iran, abstained from the U.N. Security Council vote, but did not veto the measure that was put forward by Jordan and Gulf countries and backed by the other 14 of the 15 Council members.

The Huthis have seized swathes of Yemen since they entered the capital Sanaa in September 2014 after sweeping south from their northern stronghold.

The air campaign by Saudi Arabia and a coalition of five Gulf monarchies along with Egypt, Jordan, Morocco and Sudan has so far failed to stop the rebel advance.

The U.N. resolution was the first formal action taken by the Security Council since the start of the Saudi-led bombing raids.

The resolution demands that the Shiite Huthis withdraw from Sanaa and all other areas seized during their months-long offensive.

It slaps an arms embargo on Huthi leaders and their allies, a measure that Russia sought to extend to all sides in the conflict.

The resolution puts Huthi leader Abdulmalik al-Huthi and ex-president Ali Abdullah Saleh's eldest son, Ahmed, on a sanctions list, imposing a global travel ban and an assets freeze on the two men.

The Huthis have allied with troops loyal to Saleh, who was forced from power in 2012 following a year of nationwide protests against his three-decade rule.

Russia had demanded humanitarian pauses in Yemen but the resolution fell short of that request and instead instructed U.N. Secretary General Ban Ki-moon to intensify efforts to negotiate such ceasefires.

- Tehran calls for talks -

Hadi and Gulf allies have accused Iran of arming the Huthis, which Tehran strongly denies.

Iranian Foreign Minister Mohammad Javad Zarif said Tuesday that Tehran was proposing "a ceasefire followed by all inclusive Yemeni dialogue that is facilitated by others, leading to the formation of a government in Yemen that represents a broadly based community."

Hadi, who has taken refuge in Riyadh, is considered the legitimate head of state by the United Nations, and Saudi Arabia launched the air strikes at his request.

Saudi warplanes pounded rebel positions again overnight in the battleground southern city of Aden, where Hadi had taken refuge before fleeing the country last month as the Huthis approached, residents said.

what has Iran got to do with Yemen ( An Arab State) to propose a peace plan? where was this evil rogue islamist backward country when its huthis took over Yemen by force and tried to subdue 70% of the population....

Daniel I am sure Mowati n here from Dahyeh, a good guy, only if he hadn't these 60-70 problems, in any way, he would love to add you as his wife if you can take him from Lebanon, even he, can't stand what Hizbillah is doing to this country, please take him and he will not make wear any shadour or make you clean, just rake, him he willappreciate it all his life, will Imam he will.

Daniel I am sure Mowati n here from Dahyeh, a good guy, only if he hadn't these 60-70 problems, in any way, he would love to add you as his wife if you can take him from Lebanon, even he, can't stand what Hizbillah is doing to this country, please take him and he will not make wear any shadour or make you clean, just take, him he will appreciate it all his life, will Imam he will.

ya southern, the hundreds of thousands who went on the streets in Yemen and ousted Saleh who is now allied with the Huthis were 'wahabis' and wanted to install a wahabi regime in Yemen... is that what you are saying...

The Ansarallah will make history. The world will remember how a group of oppressed people rose up and fought slavery. How they fought and pressed on despite heavy bombardments and attacks from all sides, how these honorable people are fighting with bravery are beyond imagination.

This is a real revolution and war for freedom just like we had in the Southern Lebanon 2006 July.